Circulation production process for glyphosateTechnical field
The invention belongs to technical field of pesticide, be specially circulation production process for glyphosate.
Background technology
Glyphosate is the maximum and the fastest interior absorption translocated herbicide of rate of growth of global sales, and be accompanied by glyphosate genetically modified crops succeed in developing and promote the use of and energy shortage causes sowing and the popularization of biofuel crop, for the production of glyphosate provides new opportunity.
Glyphosate (glyphosate), chemical name is N-(phosphine carboxymerhyl) glycine, and pure product are non-volatile white solid, and proportion is 0.5, fusing about about 230 ℃ greatly, and follow decomposition, the solubleness under the normal temperature in water to have only 1.2 grams, be insoluble to common organic solvents, its isopropyl amine salt is dissolved in water fully, not flammable, do not explode, storage at normal temperature is stable, centering charcoal steel, galvanized sheet iron have corrosive nature.Glyphosate is an inner sucting conduction type wide spectrum steriland herbicide, mainly suppresses enol acetonyl shikimin phosphate synthase in the object, thereby suppresses the conversion of shikimin to phenylalanine, cruel propylhomoserin and tryptophane, makes proteinic synthetic being interfered cause plant death.Glyphosate is transmitted to each position of plant after absorbing by cauline leaf, can prevent and kill off the plant of sections more than 40 such as unifacial leaf and dicotyledonous, annual and perennial, draft and shrub.Combine with metal ions such as iron, aluminium and lose activity very soon after glyphosate buries, seed and soil microorganisms hiding in the soil are had no adverse effects.
Glyphosate production mainly contains two kinds of synthesis modes, and the one, the IDA method is a starting raw material with diethanolamine or prussic acid promptly, U.S. Meng Shan waits offshore company generally to adopt this method; Another kind is an alkyl esterification method, and domestic most of enterprises adopt this method.Alkyl esterification method glyphosate production main raw material is Paraformaldehyde 96 (formaldehyde), Padil, dimethylphosphite, triethylamine, methyl alcohol, hydrochloric acid, wherein the depolymerization of Paraformaldehyde 96 is to be catalyzer with the triethylamine, through depolymerization, addition, condensation, hydrolysis reaction, after removing solvent methanol and excessive hydrochloric acid then, the glyphosate crystallization is separated out, filtration washing, filter cake is a glyphosate, filtrate is glyphosate mother solution, contains a large amount of triethylamines and hydrochloric acid in the glyphosate mother solution of this moment, and mother liquor is a strongly-acid, in order to reclaim triethylamine wherein, in mother liquor, add sodium hydroxide, regulate the pH value, the triethylamine layering is reclaimed, mother liquor behind the recovery triethylamine, owing to added sodium hydroxide, generated a large amount of sodium-chlor, glyphosate content is about 0.5-3.0% in the mother liquor.The tradition mother liquor is treated to steam and concentrates, the energy consumption height, and equipment corrosion is serious, concentration ratio is low, and the mother liquor after it is handled can only be mixed with 10% glyphosate formulation of low levels, and sodium-chlor is saturated in the aqua, the sodium-chlor long-term application causes soil compaction, and bad dispersibility causes crop production reduction.The sodium-chlor that the steam concentration obtains is not high because of content, and processing cost is big; Substitute in the liquid caustic soda and mother liquor recovery triethylamine with ammonia, form the disadvantageous effect that sodium chloride salt causes though solved, low close with triethylamine character because of ammonia alkali, similar mixing causes the rate of recovery low, and cost recovery is big; Other use part or fractional neutralization, the process complexity, and yield and cost are all undesirable.
Summary of the invention
At the above-mentioned problems in the prior art, the objective of the invention is to design the technical scheme that a kind of circulation production process for glyphosate is provided, it is effective to reclaim triethylamine, rate of recovery height, cost is low, sodium-chlor clearance height in the alkali liquor, and accomplished recycle, comprehensive benefit is remarkable.
Described circulation production process for glyphosate is produced glyphosate with alkyl esterification method, it is characterized in that comprising following processing step:
1) chlorine and phosphorus production phosphorus trichloride;
2) reaction of phosphorus trichloride and methyl alcohol generates dimethylphosphite;
3) dimethylphosphite is produced the raw material of glyphosate as alkyl esterification method, make glyphosate and glyphosate mother solution, glyphosate mother solution neutralizes with liquid caustic soda, making its pH value is 9-11, lower floor is an alkali liquor, and the upper strata triethylamine is isolated, and alkali liquor reclaims triethylamine by rectifying again, the triethylamine that reclaims adds solid sodium hydroxide dehydration back time alkyl esterification method production process to be used as catalyzer, obtains alkali liquor behind the separation triethylamine;
4) after above-mentioned alkali liquor is removed impurity through micro-filtration, ultrafiltration, adopt membrane concentration multi-stage separation treatment method to remove sodium, mould material is polymeric amide, aromatic polyamides, polysulfones, polyvinylidene difluoride (PVDF), polypropylene or cellulose acetate organic polymer, and membrane operations pressure is 1-6MPa; Alkali liquor is divided into dope and light liquid after film is handled, glyphosate content 1.0-10.0% in the dope, and sodium chloride content is less than 3%; Glyphosate content 0-0.1% in the light liquid, sodium chloride content is greater than 5%;
5) above-mentioned dope prepares the ammonium glyphosate aqua as the solvent of glyphosate and ammonia react, temperature of reaction is 40-90 ℃, stop logical ammonia or ammoniacal liquor when recording the material pH value for 4-6, preferred ammonia, according to the aqua relevant criterion, regulating and control is the add-on of may command ammonia, in ammonia feeding process, be accompanied by heat release, its heat can make solution temperature rise to about 60 ℃, and reaction process need not it is carried out cooling measure; The weight ratio of described glyphosate mother solution and glyphosate is 1: 0.01-0.2, preferred 1: 0.07-0.17;
6) light liquid is concentrated into nearly saturated or saturated solution and carries out electrolysis, electrolysis obtains sodium hydroxide solution, chlorine and hydrogen, wherein the solid sodium hydroxide that obtains of sodium hydroxide solution and the crystallization triethylamine that can be used for step 3) reclaims in the technology, sodium hydroxide solution also can in and the dilute methanol that comes out of precipitation in the alkyl esterification method production process, it is synthetic that chlorine is reused for phosphorus trichloride, and hydrogen is used for other purposes.
Described circulation production process for glyphosate is characterized in that in the step 3) in the alkyl esterification method production process, after the acid hydrolysis of glyphosate finishes, for obtaining the former powder of more glyphosate, adopt depickling and/or alkali addition process, the pH value of adjusting acid mother liquor is 0-3, preferred 1-2, used alkali is sodium hydroxide, sodium bicarbonate, yellow soda ash or ammonia, and its concentration is 3-100%, and sodium hydroxide is by obtaining in the step 6), the glyphosate crystallization is separated out, filtration washing, filter cake are glyphosate, and filtrate is glyphosate mother solution.
Described circulation production process for glyphosate, it is characterized in that earlier ammonia being joined in the dope as being acid before dope uses in the step 5), after making the dope pH value be 6-7, concentrate again, be concentrated into the 50%-80% of former weight, preferred 60-70%, should not be excessively concentrated, otherwise the soltion viscosity increase, undue thickness becomes, concentrated very few, cause energy utilization uneconomical.
Described circulation production process for glyphosate is characterized in that in the step 6) that light liquid simmer down to steam concentrates or embrane method concentrates, and ionic membrane or diaphragm electrolysis are adopted in electrolysis.
Above-mentioned circulation production process for glyphosate, the recovery triethylamine is effective, rate of recovery height, cost is low, sodium-chlor clearance height in the alkali liquor, the circulation that forms glyphosate self is produced greatly, reduce logistics cost, the comprehensive utilization ratio height reduces environmental pollution, meet the idea of development of industry recycling economy, comprehensive benefit is remarkable.
Embodiment
Now in conjunction with embodiments of the invention, the invention will be further described.
Among the present invention because after light liquid handles through film, organic impurity is stayed in the dope, and in reaction, do not have other as calcium, magnesium, sulfate radical plasma, sodium-chlor purity height can be directly used in electrolysis through after being concentrated into saturated solution so light liquid need not to make with extra care, and light liquid simmer down to steam concentrates or embrane method concentrates, ionic membrane or diaphragm electrolysis are adopted in electrolysis, because ionic membrane method gained liquid caustic soda saltiness is low, sodium hydroxide purity height, preferred ion embrane method.
Ion-exchange membrane electrolyzer mainly is made up of anode, negative electrode, ion-exchange membrane, electrolyzer frame and conduction copper rod etc., and every electrolyzer is made up of several unit groove serial or parallel connections.The anode of electrolyzer is made with ti-alloy mesh, in order to prolong electrode life and to improve electrolytic efficiency, scribbles oxide coatings such as titanium, ruthenium on the titanium anode network; Negative electrode is made by the carbon steel net, scribbles nickel coating above; Cationic exchange membrane is divided into cathode compartment and anolyte compartment to electrolyzer.Cationic exchange membrane has a kind of special nature, and promptly it only allows positively charged ion to pass through, and stops negatively charged ion and gas to pass through, and that is to say only to allow Na+By, and Cl-, OH-Then can not pass through with gas.Can prevent the H that negative electrode produces like this2Cl with the anode generation2Mix mutually and set off an explosion, can avoid Cl again2Influence the quality of caustic soda with NaOH solution effects generation NaClO.
Saturated light liquid enters the anolyte compartment; Pure water (adding a certain amount of NaOH solution) adds cathode compartment, during energising, and H2O generates H in the cathode surface discharge2, Na+Pass ionic membrane and enter cathode compartment, contain NaOH in the catholyte of derivation by the anolyte compartment; Cl-Then generate Cl in the anode surface discharge2, the light salt brine after the electrolysis is derived from anode.
2NaCl+2H2O＝2NaOH+H2↑+Cl2↑
NaOH by containing in the effusive catholyte of electrolyzer about 30% is called liquid caustic soda, and liquid caustic soda can obtain solid caustic soda through evaporation, crystallization.Another product wet hydrogen in cathodic area is sent to the hydrogen storage cabinet after cooling, washing, compression.Product wet chlorine in positive column can obtain liquid chlorine after cooling, drying, purification, compression.Liquid caustic soda or be used for whole glyphosate building-up process through spissated alkali, it is synthetic that liquid chlorine is used for phosphorus trichloride.
Embodiment one: glyphosate alkali liquor 1000g, and through micro-filtration, ultrafiltration, film obtains dope 220g after handling, and wherein glyphosate content 4.8%, light liquid 1200g, saltiness 15%.Add 95% glyphosate technicals 38.3g in the dope, feed ammonia 4g, be mixed with 20% ammonium glyphosate aqua, meet the quality product requirement.Light liquid is concentrated into 550g through underpressure distillation, carries out electrolysis and gets chlorine, hydrogen and 30% liquid caustic soda.
Embodiment two: glyphosate mother solution is handled with embodiment one, and the underpressure distillation of gained dope gets dope 165g, adds 95% glyphosate technicals 25.3g, feeds ammonia 3.5g, is mixed with 20% ammonium glyphosate aqua.Light liquid is concentrated into 550g through underpressure distillation, carries out electrolysis and gets chlorine, hydrogen and 30% liquid caustic soda.
Embodiment three: process of the test and method add 95% glyphosate technicals 11.0g with embodiment one, feed ammonia 2g, are mixed with 10% ammonium glyphosate aqua.
Embodiment four: process of the test and method add 95% glyphosate technicals 23.9g with embodiment one, feed ammonia 3g, are mixed with 15% ammonium glyphosate aqua.Light liquid carries out electrolysis through underpressure distillation and gets 30% liquid caustic soda, chlorine and hydrogen, and liquid caustic soda is condensed into solid sodium hydroxide.
Embodiment five: process of the test and method add 95% glyphosate technicals 14.7g with embodiment two, feed ammonia 2.5g, are mixed with 15% ammonium glyphosate aqua.
With the yellow phosphorus heat fused, feed chlorine, generate phosphorus trichloride (crude product).
2P+3Cl2＝2PCl3
The crude product phosphorus trichloride obtains the finished product phosphorus trichloride through rectifying, phosphorus trichloride and methyl alcohol react dimethylphosphite (crude product).
PCl3+3CH3OH＝(CH3O)2POH+2HCl+CH3Cl
The crude product dimethylphosphite obtains the finished product dimethylphosphite through rectifying.Methyl alcohol, triethylamine and Paraformaldehyde 96 generation depolymerization reaction, add glycine generation addition reaction, add dimethylphosphite generation condensation reaction, add the reaction that is hydrolyzed of 30% hydrochloric acid then, precipitation (methyl alcohol) depickling adds liquid caustic soda and carries out pH and be adjusted into 1-2, crystallization, suction filtration obtains glyphosate wet-milling and glyphosate mother solution.Glyphosate mother solution adds liquid sodium hydroxide neutralization, and making its pH value is 9-11, displaces triethylamine, and lower floor is an alkali liquor, and the upper strata is a triethylamine, takes out triethylamine, adds the dehydration of solid sodium hydroxide and leaves standstill the back to return glyphosate synthetic.Glyphosate mother solution rectifying goes out triethylamine and returns the glyphosate mother solution neutralization.